Re: PROBLEM: Deadlock in attach_device() in AMD IOMMU driver

[Gregor Dick <gdick-s/n/eUQHGBpZroRs9YW3xA@public.gmane.org>]

Hi Joerg,

On 05/05/15 15:41, Joerg Roedel wrote:
> Do you see a real deadlock or only the lockdep warning? In the code it
> looks like virtfn_add() takes the sriov->lock of the physical device
> while pci_enable_ats() (when called from there) takes the sriov->lock of
> the virtual function. In this case it couldn't deadlock.

The thread does deadlock. It looks like pci_enable_ats() takes
dev->physfn->sriov->lock, where dev is the VF. I'd understood this to be
a lock protecting SR-IOV state for all VFs configured on the PF (but I'm
not familiar with the code at all!).

Thanks,
Gregor
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